244 Malcolm ( ·. Coulter IC/11' Technical J'uhhnllion /•io. 2, J1JS4
THE CONSERVATJON STATUS OF PERUVJAN ACKNOWLEDGEMENTS SEABJRDS
1 wish to thank the Charles Darwin Rcsc·lrch St·ttio , , .. Gahipagos for support of my efforts to s<:vc ·t ,Jil.1Cl ScrviCIO 3 t!~c' ~~ ~he Parq~JC ~acional 1 2 and the F:cuadorian Government for funds I ~)e lC .ctm to the World Wildlife Fund DAvm CAMERON DuFFY , CoPPELIA HAvs & MANUEL A. PLENGE Council for Bird Preservation for support I~·.,,
REFERENCES ABSTRACT
BoERSMA,43--93. D. 1976. Atl ceo ]og!ca · 1atH j 1lchav!oural study oft he Gahlpagos Penguin. Uving IJird 15, Peru, in the past, had some of the largest and economically most important seabird populations in the world. Ovcrlishing in the 1960s led to a decrease in bird numbers and to a collapse of the fishery COULTER, M. C., DUFFY, D. c. & HAI{COURT s ]l) '. . in the 1970s. Possible recovery of flsh stocks has apparently been prevented by continuing fishing --Santa Cruz, 1981. Noticiasde Galtipa •os3s' 24 JH2. St.l!us of the Dark-rumpcd Petrel on Isla pressure. Poaching of eggs and young and mortality in flshing nets arc also problems, but persistent l·OSBFHC F R 19(:'i N . g , . 1-l~RJ~;s,'M .. P ..196;· :fl ':'rrai hml r:~fu~cs in the C!altipagos. Elepaio 25,60--7. pollutants and oil do not seem to be. Habitat destruction is also minor, except for continuing 37, 95--166. . w lro ogy oJ storm petrels rn the Gahlpagos Islands. Proc. Calli A cad. Sci. damage to the few estuaries on the desert Peruvian coast. Estimates of species' breeding numbers, and location of the important, known colonies, arc presented. The species in greatest jeopardy HAHH!S, M.P. 1970. Thebiologyofancndangcrcd .•.·,. I, .... appear to be the Humboldt Penguin and the Peruvian Diving Petrel. Further details of both species plweopygia), in the Ga!habitats es minima, con excepci6n de unoS pocos estuarios en el desierto de Ia costa peruana. Estimaciones del nlnnero de espccics anidando y Jocalizaci6n de colonias de gran importancia, han sido prcscntadas. Las especics en mayor pc\igro pareccn scr, el Pingliino de Humboldt y el Potoyunco, de los cmlies sc necesitan nuis detallcs urgcntementc. Asf como tambiCn, las siguientes investigaciones: 1- detenninar las dietas actualcs de las especies productoras de guano y del Pingliino de Humboldt; 2- las ventajas rc!ativas econ6mica y socialmente de Ia harina de pcscado, del guano y de Ia pesca para consumo humano; y, 3- idcntificaei6n de cstuarios importantcs y sus problemas. Una sola y neccsaria acci6n directa a trav6s de medios cientfficos y polfticos, debe ser tomada, con cl lln de detener Ja sobrepesca del stock sobrevivicnte. Zonas de pesca fuera de Ia costa pcruana, actualtnentc no explotadas, deberian ser expanderse y protegcrsc. 245 246 D. C. Duffy, C. Hays & M.A. Plenge Peruvian Seabirds 247 INTRODUCTION
Most of the productivity of the oceans takes place along the western coasts of contincm\ whe re wind-generated upwe llings bring nutrients to the surface. These nutrients fuel short but very rich food chains with most of the e nergy passing through just one specic 1 of fish. These te nd to be anchovies (Engraulis) or sardines/pilcha rds (Sardinops (Cushing 1971, 1975). The high productivity supports very large stocks which are further concentrated in dense shoals accessible to predators. These upwe lling a reas suppon great numbers of reside nt and migrant birds, marine mammals, and many of the Iargc11 ...... I single-species commercial fishe ries (Cushing 1975). \,...... ,., The Humboldt or Peruvian Coastal Current has been one of the most productil'c these upwellings, supporting the largest single-species fi shery on earth (Idyll 197! immense numbers of birds (Murphy 1925, 1936; Vogt 1942; Jordan and Fuentes 196!· and a major mining industry based on avian guano (Hutchinson 1950). A ll ofthcseh,,. been based on a single species o f fi sh, the A nchoveta (Engraulis ringens). 1 conservation of Pe ruvia n seabirds is essentiall y the conservation of Engraulis ringem its populations remain viable, the birds a nd the commercial fi shery dependent on remain viable. Unfortunately, in the earl y 1970s the Anchoveta stock collapsed becac
of overfishing and environmental change (Idyll 1973; Valdivia 1978) with dcvastar1 effects on the birds (Tovar 1978) and commercial fi she ries (Idyll 1973). Whether. Pia. Aguj ecosystem can recover from this and regain its high productivity remains in dour· Lobos ,; decade Ia ter. de Tierra
CURRENT STATUS OF PERUVIAN SEABIRDS Except for the three guano-producing species (see below), we know almost nothmt the numbers of Peruvian seabirds. In several cases, we do not even know the breed locations of the species. Most of coastal Peru is desert, with few roads to facilitateaC\: Many of the species nesting on the mainland use cliff-sites which discourage ca1 investigation. Most of the other species are on coastal islands protected b) t government. T ransportation to islands is difficult to arrange even if the necc:\ permits can be obtained. This discourages visits by bird-watchers and others 11h<> responsible for so many distribution records in other areas. Serious workers ha\Cte to concentrate on the guano-producing species both because of their economic rmp; ance and because of the ir uniquely large colonies (e.g. Coker 1919; Murphy 1925.\ 1942; Nelson 1968; Tovar 1978). T his review of the status of resident Pe ruvian seabirds is a very subjective docu based on impressions from our fi eld work. For each species, we have estimated maximum number of breeding individuals to the nearest order of magnitude, and n.: the areas of known or suspected abundance. Details of existing counts and cstimatn given in Table 1. Figure 1 shows important localities mentioned in the text.
Humboldt Penguin (Spheniscus humboldti). Estimated maximum number of br 4 individuals: 10 • Listed in Appendix 1, CITES, as e ndangered. Small numl'om breeding penguins can be found along most of the cliff sections of the Pcruvaan Larger numbers occur only at Pachachamac and Punta San Juan. Report' ol numbers at Lobos de Tierra and Punta Pampa Redonda are probably optimi'11'
Peruvian Diving Petrel (Pelecanoides gamotii). Maximum number of brccdin~ 1 Figure J: I 4 mportant breeding localities of the major Peruvian seabirds. uals: 10 • Insular colonies are known only from Lobos de Afuera, San G a lfa n~ Yieja, but small colonies may a lso exist on Chincha Norte (Galarza 1968) and (Tovar 1968). Colonies on the mainland have been reported, but without dct~ species may be, with the Humboldt Penguin, of most concern among those rc' Table 1: Recent census data for Peruvian seabirds. Species Site Latitude Date Adults Humboldt Penguin Source Lobos de Tierra Sphcniscus hwnboldti 6~25'5 Feb 1979 5 D. Duffy Dec 1980 1.000 PESCA PERU Mar 1981 900 PESCA PERU May 1982 5 Mazorca C. Havs JP30'S Dec 1977 50 D. Du'ffy Dec 1980 150 PESCA PERU Mar 1981 120 July 1981 PESCA PERC Pachachamac 8 C. Hays !2°19'S Dec 1980 600 PESCA PERU Mar 1981 750 PESCA PERU July 1981 320 Ballestas C. Hays 13°44'5 Mar 1969 35 Ridgelv & Eisenmann Aug 1976 2 Ridge!)· May 1978 10 D. Duffy June 1978 19 D. Duffy June 1978 0 D. Duffy July 1978 1 N. Atkins Mar1981 8 PESCA PERU Jul1981 9 Punta SanJuan C. Hays 15°2]'$ Dec 1980 3.680 PESCA PERU Mar 1981 2.220 PESCA PERC Jul198l 2.000 Punta Pampa Redonda C. Hays 15e50'S Dec 1980 1.800 PESCA PERU Mar 1981 300 Ju! 1981 PESCA PERC SanGa!lan 0 13°50'5 Jul1981 C. Hays La Vieja ll1 C. Hays 14°17'5 Jull981 8 Santa Rosa C. Hays 19°!9'S Ju! 1981 0 21 islands and headlands C. Hays Dec 1980 6.504 21 islands and headlands PESCA PERL' Mar 1981 4.770 11 islands and headlands PESCA PERC Jul198l 2.608 Peruvian population (total) C. Hays Galapagos Storm Petrel 1981 San Gal!an 4.000--5,000 (min.) C. Hays Occanodroma tethys 13°50'5 Ju! 1978 present. presumed nesting D. Duffy Peruvian Divmg Petrel Mazorca !!~30'S Jan !978 Pelccanoidcs gam01ii La Vieja present. population probably small 1n7'S 1962-5 D. Duffy SanGa!!an 1.000 individuals nesting 13~50'5 Jull978 Tovar (1968) Chincha Norte 5.{Xl0pairs(max.) Peruvian Pelican !3°39'$ no date D. Duffv Peruvian population heard at night Galarza-(1968) Pe!ecanusthagus 1981 c. 800.000i~dividuals see text Blue-footed Booby Lobos de Tierra Sula nebouxii 6<>:25'5 Feb 1979 lS,OOOpairs D. Duffy ·.:,, Peruvian Booby Peruvian population ... 1n1 c. 4mil\ion individuals •••'\ .•·.• ..• .. ·.•.·· Su.Ia l'aricgata SCC\CXt ·.~·~ O!ivaceous Cormorant Ba11cstas u~4~'s Nov 1963 40nests Tovar(1968) Ph a/acrocorax o/iw1ccus Mar 1979 50pr Guana\·Cormorant D. Duffy Peruvian population 1981 c. 3 million individuals sec text Phalac~ocorax bougainvillii Red-legged Cormorant Lobos de Tierra 6"25'S Dec 1963 2pairs Tovar(1968) Phalac;;corax gaimardi Guai'i
("'""" ··--·--,·y-7"'-· ···· ·' '""··- "-~-,"-:
1 The guano birds. Guanay Cormorant (Phalacrocorax bougainvi!lii): maximum breeding Peruvian Tern (Sterna /orata): estimated maximum breeding individ~1als: 10.· • This 7 individuals: 10 • Peruvian Booby (Sula variegata): maximum breeding individuals; 106 . , ecies with its small colonies and dispersed nests, is probably the Pcruvmn seabird best for mainland nesting. It occurs along the entire Peruvian coast from Talara to Peruvian Pelican (Pelecanus thagus); maximum number of breeding individuals: 106. ~1 ~apted The combined population of three species was 8,300,000 in 1981, the most recent Arica, Chile. available census (EI Commercia, Lima, 10 April 1982). The percentages of each species were not given, but based on recent work by Tovar (1978), boobies were likely to Smith American Tern (Sterna hinmdinacea): breeding numbers unknown. Koepcke represent about 50 percent; cormorants, 40 percent; and pelicans, 10 percent. These (1970) reported this species only as a visitant in the Lima. ar~a. Beck (Murphy 19_36! h~ld percentages arc quite different from those reported by Jordan and Fuentes (1966). earlier collected birds in breeding plumage at A neon, wJtlun Koepckc's area. SJmilaJ ly Tovar (!978) hupwelling waters and low-productivity warm waters. During visits in December, January, and February, pairs were found at all Historical trends stages of the breeding cycle (Murphy 1936; Tovar 1968; Duffy, pers. obs.). If this species Population trends arc virtually unknown for any except the three main guano-producing nests throughout the year, the breeding population will be much bigger than estimates species. The main historical influences on numbers appear to have been human, based on single visits. centering on the usc and misuse of the guano islands. In pre-l1ispanic times, the islands were protected by Inca law. Some guano was Heel-legged Cormorant (Phalacrocorax gaimardi): estimated maximum breeding indi 1 harvested (Vogt 1942) but the only other known uses of islands were as sites for fertility viduals: 10· • This solitary-nesting and foraging species is nowhere common, but is so rites (Buse 1972). Following the arrival of the Spanish, eggs were used extensively in widely distributed along the coast that, despite its small numbers, it is in no immediate mortar for construction in Lima and probably in other towns along the coast (Plcngc, danger. unpubl.). Extensive guano mining probably first occurred in the mid-18th century (Murphy 1925; Hutchinson 1950). Mining took phlce throughout the year, preventing Olivaceous Cormorant (Phalacrocorax o/ivaceus): estimated maximum breeding incli 1 breeding. Adult birds were in any event used to feed the workers. Burrowing species viduals: 10' . This species is rare in the upwelling area where it seems dependent on such as Inca Terns and Peruvian Diving Petrels had their nesting substrates almost sheltered coastlines and estuaries. It may be much more abundant in the warmer waters completely removed. The removal also probably decreased t!1e population of hole of northern Peru. nesting Humboldt Penguins (Murphy 1925) altholJgh this species may have used surface nests, as docs the Jackass Penguin (Spheniscus demersu.s) in southern Africa. Magnificent Frigatebird (Fregata magmjicens): population in Peru unknown. This By the turn of the century, all guano island species were very rare and the guano species may nest in the northern mangrove thickets. Birds \:iecn in Peru may, however, deposits were almost exhausted. The Pcruvi
24
20 Anchoveta
Sardina
16
12
8
4
€5 67 69 71 73 75 77 79 81 0 10 20 30 Years 1965- 1981 40 50 60 70 80 YEARS 1909 -1901 Figure 3: The increasing importance of !he Sardina (San/inops sa;;ax) as stocks of Anchovc\n (Engraulis ringen1·) have fallen. Figure 2: Changes in the estimated total seabird population of the Peruvian coast and islands since the inception of the national management company. Source: El Comercio, 10 Aprill982. Peruvian coast for human recreation, and Peruvian Tern populations may have declined locally as a result. The establishment of chicken farms south ~f ~ollendo has caused a 'considerable decline of this species in recent years' (Hughes, m htt. ). . . markedly to as many as 30 million birds (by some estimates) from previous populations The Grey-hooded Gull may be the only Peruvian seabird actually mcr:asmg. of no more than eight million (F;gure 2). Numerous breeding sites have been discovered since the ~r?t colon~ was found m ~967 In the 1950s, the introduction of inexpensive purse seines and the importation of fish at Laguna Chica (Tovar and Ashmole 1970). For the remammg spccJCs, we have no 1dea meal plants from the collapsed sardine industry in California Jed to the creation and of current population trends. J~apid growth of a commercial fishery centered on the Anchoveta (Idyll 1973). The f1shcry then went on to become the world's largest in the late 1960s (Schaefer 1967; Idyll 1973). The commercial fishery may have killed many birds in nets, but the most THREATS FACING PERUVIAN SEABIRDS important effect seems to have been a reduction in reproductive success of the guano birds; only certain islands were close enough to the remaining areas of high Anchoveta Dil·ect exploitation . . . density to permit successful reproduction (Duffy, 1983). Egging occurs, although it seems from conversatJOns w1th guards ?n the 1slands that During the 1970s, the fishery collapsed with Anchoveta stocks reduced to one-quarter disturbance rather than the egging itself does the most damage. Dunng 1977.' one ~mall of their previous levels (Valdivia 1978). Guano bird numbers, already low, fell to two island with 20,00()-30,000 pairs of pelicans and cormorants was deserted followmg a million (Figure 2). The effect of the collapse on the other bird species is unknown. single visit by egg collectors (Duffy, pen;. obs. ). Fortunately, because of guards on most islands, egging appears to be infrequent. The low pay of the ~uards makes some of them Current trends susceptible to offers to buy young birds for resale on the mamland. In 1977~79, at least Anchoveta have never recovered from the 1972 collapse, and ovcrfishing has continued two islands were involved (Ortiz, pers. comm.):' . on the surviving stocks (Valdivia 1978). It now appears (Figure 3) that the Sardina Adult Humboldt Penguins were until 1978 routinely considered part _of the d1et of (Sardinops sagax) is replacing the Anchoveta (e.g. Jordan eta/. 1978)) Anon. 1980) as guards on the islands. They were usually killed on the nest, thus also cau_smg the d~aths it has elsewhere (Daan 1980). Unfortunately, the apparent increase in Sardina may in of any eggs or dependent young. On Isla Mazorca and its satelli~e iSlands, With ~ part come from deliberate misidentification of landed Anchoveta. In any event, guano maximum population of perhaps 400 birds, between 70 and 200 were killed per year until birds have begun increasing again (Figure 2: El Comercio 10 April1982). 1978. The Humboldt Penguin seems to be decreasing, probably as a consequence of the Peruvian Diving Petrels arc also eaten during guano extraction periods on Isla La overfishing and catches in nets. The last two decades have seen an opening-up of the Vicja (Tovar 1968) and perhaps also on brief visits to San Gallan by local fishermen (Murphy 1925). 254 D. C. Duffy, C. Hays & M.A. Pleuge Peruvian Seabirds 255 ·--- ·------
Kocpckc & Kocpckc (1963) believed exportation of Humboldt Penguins to outside Predators . . zoos to be a threat to the population. Hays (1982) summarized export figures from 1973 Black Rats (Rattus rattus) have ~ccurred on several Js.lands but appear to have little or until exportation was prohibited in 1977 as follows: 1973-598; 1974--608; 1975~478; effect on the larger b1rd spec1es (Vogt 1942). Then· effect on Inca Terns and other no l . . I 1976---480; 1977--484. At least 2728 birds were exported over the five years. England smaller species has never )een mvestJgate( . . was the destination of 28 percent of the penguins: the rest were distributed Cats were until recently kept on some islands. Feral cats on Lobos de TJCrra m.ay take , ung boobies (Vogt 1942; Duffy, pcrs. obs.). Dogs arc kept as pets on many Islands. Netherlands, 18 percent; Japan, 14 percent; West Germany, 12 percent, and United 0 States, 11 percent. Gailey-Phipps (1978) recorded only 196 Humboldt Penguins on Lnfortunately, even trained dogs will attack birds. exhibit in zo.os in 1974. Many of these zoos reported successful reproduction, suggesting Murphy (1925) reported tracks of 'Zorn/, presumably a native fox, on San Gallan. zoo populatJons CHll and should be self-sustaining. No such tracks were found in 1979 (Duffy & Hays, pcrs. obs.). The most dangerous potential 'predator' is disease. Domestic pigeons and chickens Incidental catches in nets were kept on many islands until recently and may still be present (Vogt 1942; Duffy, At the height of the fishmeal industry, many birds were reportedly killed in nets set for pers. obs. ). These are potential sources of such diseases as f.owl cholera and. Newcastl.e's Anchovcta (Jordan & Fuentes 1966). Unfortunately this was never quantified. disease which would be devastating in the dense colomes of guano bu·ds. Dunng Penguins and Red-legged Cormorants are caught in drifting gill-nets set for turtles, population crashes, pelicans may invade farms and cities looking for food (Jordan & porpoises, and large fish. The extent of this is also unknown. Fuentes 1966; Leek 1973) and become exposed to disease.
Competition with commercial fisheries CONSERV AT! ON ACTION AND REQUIREMENTS As mentioned in previous sections, bifds and humans competed for Anchoveta before the collapse of the fishery in the early 1970s (Schaefer 1967, Duffy, 1983). We do not Previous and existing efforts know the present diets of the guano birds. They may still be feeding on Anchovcta which Since 1909, the islands have been protected by the state~owned guano company. More the commercial fishery is forbidden to take, or they may be competing with the fishery than anything else, this company and its successors have been resp?nstble ~or tl~e for stocks of Sardina. Since these arc now being overfished (Anon. 1980), the recent conservation of the seabirds of Peru. The company provided guards for 1slands; filled m increase of the guano bird population may stop. gullies and otherwise improved nesting habitat; fenced. off headlands with predator An ominous potential new threat h On the mainland, only the Paracas peninsula and 900ha of the Mejia estuary are now protected as nature reserves by the government. Table 2: Prio rities of Peruvian seabird conservation: a summary. I. Species of most co~ cern Present a nd future requirements (See summary, Table 2) I. Humboldt Pengum We need to know more about the distribution and approximate numbers of non 2. Peruvian Diving Petrel guano-producing Peruvian seabirds. Except for the Humboldt Penguin we have only a II Priorities for census and distribution efforts haphazard and superannuated collection of breeding records, usually lacking even · Regular census of the Humboldt Penguin . . . estimates of numbers. Colonies of gulls, terns, cormorants, and diving petrels should be ~: Location of colonies and preliminary census of Peru vian Dlvmg Petre 1 estimated to at least an order of magnitude. The distribution of Peruvian Terns should 3 Censuses of all island-nesting scab ~rds . be determined with identification of the largest breeding concentrations. PESCA 4. Location and relative sizes of colomes of Band-ta1led ?ull T 5: Location and relative sizes of colonies of South Amencan ern PE RU or IMARPE should consider attempting estimates of breeding populations of all 6 Distri bution of Peruv1an Tern . seabirds on guano islands. Much of this information may already exist in the fi les ofthese 7: Location and relative sizes of colonies of Ohvaceous Cormorants organizations but it sl)ould be published. The population counts of guano birds should be given separately, by species. 111. Necessary research p . Booby Peruvian Pelican and Humboldt Penguin ~: ~~~=;;~~::~~~~~i~~sgo:a~~~~:~;:~~~~a~:h in~~;;~uman cdnsumption Necessary research 3 Identification of critical estuanes and threat ~ to them The following actions are needed as a matter of urgency: 4: Inventory of zoo stocks of Humboldt Pengum 5 A life history study of the Peruvm n D1vmg Petrel . d f d . S rve s of markets in Peru to determine frequency of seablr s as oo . - The diets of the three guano-producing species and the Humboldt Penguin should ~: ~eter~ in at ion of disturbance levels at mainland and other seab~rd colomes be investigated to see if they have switched from Anchoveta to Sardina. IV Direct action r · 1 - Market surveys should be made along the entire coast to estimate how many I .Prevent overfishing using scientific arguments and po ltlca pressure penguins and other seabirds are being taken in fi shing nets, or by poaching. 2: Enforce and expand no-fishing zones . - An economist should investigate the relative economic and social benefits of 3. Provide better training for guards 0 1~ guano tl s l:~~~~~e r a l cats on guano islands fishmeal, guano, and fishing for human consumption. 5.4. ConReducetinu ehuman effort sdi !soturbance control and at co er lo adm~ escate on r:h~ mainland' especially in parks and reserves - Disturbance levels at colonies of gulls, terns and diving petrels should be determined. The effect of off-the-road vehicles on colonies of Peruvian Terns at the Paracas National Reserve should be investigated, perhaps as part of a larger . 1 d •t . Disturbance is minimal on the study on the effect of these vehicles on archeological ruins and on vegetation. Reduction of di sturb~nce on ~sl~~ds an~ m~·~f a:Cf-~~ =~;oad vehicles is necessary in the - Important (i.e. surviving) estuaries should be identified with some estimate of guano islands. Fencmg or Simi ar con ro . more protection if tourists begin visiting bird use and assessment of the types and magnitudes of threats to each estuary. Paracas Rese~ve. Isla San Ga l: a ~·~1 ga~ur;~~~t~al numbers of diving petrels. Suggestions - A world-wide inventory of Humboldt Pengui ns in zoos should be undertaken ~~e~~~~~~it~~ ~~~~~~;;~o~~~t i ~ n mu st await the surveys of main land si tes. with an attempt to consolidate individuals in to viable captive populations. - A life history study of the Peruvian Diving Petrel should be undertaken as soon Th e ent programme of shooting gulls and as possible. Control or elimination of predat)oh. ld b~ ~:s;ended until investigations demonstrate Turkey Vultures (Cathartes aura s ou v· .t to the Band-tailed Gull colony on San Direct action that these birds are, in fa~t, prob:~~s. lSI s ded until the size of the population of this Preservation of existing habitats. As a first step, better-trained guards are needed on ~~~~fens f~r ~nu~~~~e~~~-~~~~~r~~~~~rts ~ ~~~~~:onti~~~~ ~~~h~i7~i~:~e~ ~ ~~:~· ~oo;;: ~~ islands. Training courses at regular intervals would improve the efficiency and morale of i~prove .the q~a l itydofifshh· feo :~a~~; ;~~;d~h ~~t~:t s are nocturnal so shooting would be guards, and even the distribution ofVogt's (1942) Aves Guaneraswould be a great help. T1erra usmg p01sone · Secondly, the present laws prohibiting fishing within three to five miles of guano islands ineffectual. should be enforced. The Peruvian Navy has the capability to protect a 200-mi le fi shing . I . . he most urgent task-and the most difficult. zone, so it should be able to enforce limits much closer inshore. Radio communication Prevention . of ~verfish mg . T liS IS t hat"takes into acount the strong probability from islands to the mainland is now possible and should also be employed in enforce Fisheries biOlogists must ~evelo~ ~o':od~; i :ion of fish-landings. Catch levels should be ment. Thirdly, a commission should investigate how the guano islands could be made of fraudulent reports on SIZe an . P f ·tment failure A more far-sighted greater tourist attractions without damaging them. Conservation that is not of economic sufficiently low for fish stocks .to ~ u rfivlhve a ylear ocl r~~[~~ in favour of fishi ng for human benefit to the country can be difficult to justify. fishery management might lumt s mea pro u consumption and guano. II h fi h cal fa ctories and can thus control the Creation of additional habitats. No-fishing zones within the Para cas National Reserve P ESC~ PERU presently owns a t e P~S~A PERU to the private sector would (closing Bahia de La Independencia to purse seiners) and extended no-fishing zones fish meal mdustry. The prop~s~d sai\of lo ical disaster of the 1970s. If the Sardma around Isla Mazorca, Isla Macabi, Isla Santa Rosa, and Punta San Juan would prevent almost certainl y mean a t e gto be smaller and even more vulnerable local overfis hing by purse seiners. r ep~t l tJO n ~ fi~~ l itos rme ~1sl macianagemen g the Ann tc. hl of vbeottah, ~~~~~~:t =~~ld Sa~d in a are fis hed out, zooplankton or jelly 258 D. C. Duffy, C. Hays & M.A. Plenge Peruvian Seabirds 259 fish might become the dominant constituents of the community, and the upwelling might ------. --·······-- ·--- -- acquire longer food chains which would not lend themselves to avian or human exploitation (e.g. Walsh eta/. 1980). N N. 1980. A review of replacement of deplete'd St<:c.k. s b~ other. lor speciesMer. 177' and 405-21. the mechanisms National and international conservation organizations should develop lines of com~ J)~~d~rlytng such replacement. Rapp. P. ·<': Reun. (on~; ,;;lp;,~~ Ar~lui69, 109-13. DUFFY, D. C. 1981. fishing: effects on Peruvian guano munication to Peruvian scientists to ensure that scientific advice and warnings arc not DUHY,. D · C · 1983 · Envtronmenta!Sea~onal change~~ unce1 t~~ tam ~et<~b_trc~f:~~~~'mercial Yan c ignored in the political arena. Overfishing, and the destruction of the renascent fish 8 stocks, may only be preventable if lobbies in countries buying fishmeal vociferously birds. Bioi. Com·~rv. ~6tJ2i9~9: A second breeding record for the Grey-hooded Gull (Larus express a willingness to work for higher tariffs on fish meal or the boycotting of firms and f)UFFY, D. C. & A TOVAR,H.l968.Areasdc!Cp10birds. Condor 83, 209-1~ .. d UC!{IlY.·) d"lS ·t rJ).1 uci()n de las aves marinas en ellitoral peruano. Hoi. 5 REFERENCES Instil. Mar. PenJ-Callao 526--4 : , . , ... , )S ddos rcproductivos de 1969/70 a TovAR H. 1978. Las poblacwn~s1(1~), de tlves guancJas en 1' ANoN. 1970. Report of expert panel on the economic effects of alternative regulatory measures in 1973f74. lnf. lmtit. Mar. Peni-Callao 45, :-13.d. , cecord for the Grev·hooded Gull, Lams the Peruvian anchoveta fishery. Inforrne Inst. Mar 34. TOVAR, H. & ASHMOLE, N: P. 1970. :A ll~e2u~19-22 , 7 ANoN. J 980. Informe de evaluacic)n de los recursos pcsqueros anchoveta, sardina, jure] y cabal!a a cirrocephalus on the Pcruvtan coast. Cond?' ' , . ·. 'lting hrge quantities of marine fish. julio de 1980. lnforme lnsr. Mar78. llJRNER,, M . D . eta/' . 1980 . MethylmercuryII 35 367 m78 popu 1atJons e, , BusE, H. 1972. Epoca prehisl<5rica. Vol. 2. Historia Maritima del Pen!. 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